Member Need to Know – Civil Aviation Safety Alert (CASA) 2025-14
Transport Canada has published a new Civil Aviation Safety Alert - CASA 2025-14 - titled Potential Risk of Interference of 5G Signals on Radio Altimeter – Update on the 5G Spectrum Environment in Canada Meteorological Tower (MET) Notification.
Purpose
This Civil Aviation Safety Alert (CASA) provides an update on the 5G spectrum environment in Canada. Major telecommunications service providers in Canada have voluntarily agreed to postpone the sunset of existing 5G mitigation measures until June 30, 2026. This provides additional time for Transport Canada (TC) and Innovation, Science, and Economic Development (ISED) Canada to work with the aviation and telecommunication industries, including the Original Equipment Manufacturers, on next steps prior to lifting the mitigation measures in a safe manner based on scientific data and analysis.
In 2024, TC issued Airworthiness Directive (AD) CF-2024-14 (for fixed-wing aircraft) and CF-2024-15 (for rotorcraft) that describe current Radio Altimeter (RadAlt) tolerance requirements in Canada. These ADs remain effective while current 5G mitigations are voluntarily maintained by Canadian telecommunications operators.
Upcoming 5G environment:
Although Telecommunications operators have agreed to voluntarily extend existing 5G mitigation measures until June 30, 2026, an aircraft may be subject to stricter aviation limitations and/or retrofit expectations due to the sunset of current 5G mitigations. On January 1st, 2028, remaining spectrum mitigations will also sunset, which may further alter aviation limitations and/or retrofit expectations. Further details on the 5G mitigations being sunset are included in Appendix D.
Ongoing recommended action:
- TC urges all operators to retrofit their aircraft to meet RadAlt tolerance requirements described in ADs CF-2024-14 (for fixed-wing aircraft) and CF-2024-15 (for rotorcraft) by securing maintenance slots, parts, and supplemental type certificates (STCs) if necessary.
- In the event of an actual disturbance of radio altimeter, it is imperative that flight crew report the event to the Air Traffic Service as soon as possible, regardless of the location of the occurrence be it domestic or foreign airspace. Pilot in command and operator are to complete the ‘Radio Altimeter Disturbance/Interference Report’ in Appendix C: Radio Altimeter Disturbance/Interference Report. RadAlt Disturbance/interference Reports would assist TC in assessing 5G interference and are strictly non-punitive. Operators reporting RadAlt disturbance/interference will not be penalized where irregular flight operations are caused by a malfunctioning RadAlt. TC is thankful for the voluntary cooperation of all operators in this process.